10.6.2 The recv() and timeout() Methods

The []recv method is not defined here, as this agent
represents a request function and will generally not be receiving
events or packets10.1.
By not defining the []recv method, the base class version
of []recv (, []Connector::recv) is used.
The []timeout method is used to periodically send request packets.
The following []timeout method is used, along with a helper
method, []sendit:

The []timeout method simply arranges for []sendit to be
executed every interval_ seconds.
The []sendit method creates a new packet with most of its
header fields already set up by []allocpkt.
The packet is only lacks the current time stamp.
The call to []access provides for a structured interface to the
packet header fields, and is used to set the timestamp field.
Note that this agent uses its own special header (``ECHOHeader'').
The
creation and use of packet headers is described in
later chapterChapterchap:pformat;
to send the packet to the next downstream node, []Connector::send
is invoked without a handler.